fix locale 404 not default

src/components/Login/index.js

@@ -59,7 +59,8 @@ class Root extends React.Component {
     }
 
     componentDidMount() {
-        let lang = navigator
+        let slang = sessionStorage.getItem('lang');
+        let lang = slang || navigator
             .language
             .substring(0, 2);
         fetch(`/locales/${lang}.json`).then(response => {